ESP32 TIPS

Here we share some information on how to deal with situations that can arise while you experiment with ESP32s.

SSL stops working after Arduino libraries update

There seems to be an issue with WIFi101 or WiFiClientSecure and the use of certificates. Using the previous revisions (from before April 2021) kept things working fine.

MD5 Error

After successful compilation and file transfer, Arduino IDE displays error:

MD5 of file does not match data in flash

This error has several causes. For us, it was caused by a 3K3 pull-up resistor on GPIO12, which is pulled down during boot. We were lucky that we use that input for a button, so it was sufficient to keep the button pressed (input to ground) to get the device to reflash. A higher value of 22K should still allow handling the external pull-up and work for boot (needs tested).

Watch this guy!

These shields that you can find online work like a charm to program your ESP32 Cam, however some have a nasty defect in the PCB: the GND pins are not all shortened, and they don’t work well if you shorten them externally.

So, after you program them successfully, if you try to install just the Camera module in a different shield, that most likely has been designed shortening GND all around, IT WILL NOT WORK!!!